1. betide. Happen,chance,occur refer to the taking place of an event. Happen, which originally denoted the taking place by hap or chance, is now the most general word for coming to pass: Something has happened.Chance suggests the accidental nature of an event: It chanced to rain that day.Occur is often interchangeable with happen, but is more formal, and is usually more specific as to time and event: His death occurred the following year.

mid-15c., "chance, luck," from present participle of happen; meaning "occurrence" is 1550s. Sense of "spontaneous event or display" is from 1959 in the argot of artists. Happenings "events" was noted by Fowler as a vogue word from c.1905.

happen

v.

c.1300, "to come to pass, occur," originally "occur by hap, to have the (good or bad) fortune (to do, be, etc.);" see hap (n.). Replaced Old English gelimpan, gesceon, and Middle English befall. In Middle English fel it hap meant "it happened." Related: Happened; happening.